FIELD OF THE INVENTION

[0001] The present disclosure generally relates to polymerization processes. Specifically, the present disclosure relates to processes for polymerizing alpha-olefins to produce poly (alpha-olefins).

BACKGROUND

[0002] Poly (alpha-olefins) are typically used in a range of applications such as candles, mold release, and personal care applications. Historically, these poly (alpha-olefins) have been produced from feedstocks having a carbon number range of less than 24, from C24 to C28, or C30+, e.g., as shown in U.S. Patent No. 4,060,569, U.S. Patent No. 4,239,546, and U.S. Patent Application Publication No. 2004/0040200. Such feedstocks are commercially available from Chevron Phillips. Nevertheless, a continuing need exists for poly (alpha-olefins) with improved performance and greater flexibility, particularly for poly (alpha-olefins) having melting or softening points in the 56-70°C range with high linearity, e.g., greater than 85%. Conventional materials typically have melting or softening points outside this range. Conventional linearities are typically less than 72%.

[0003] It has unexpectedly been discovered that the poly (alpha olefin) produced by the process of the present subject matter is able to lock fragrance oil, and improve paraffin melt properties in fully refined and semi-refined paraffins. It also controls burn properties, opacity, and hardness of paraffin waxes with melt points > 130°F.

[0004] Further, typical poly (alpha olefins) commercially available only perform well with paraffin waxes having melting points of less than 130° or >140°F. However, it has unexpectedly been found that having a poly (alpha olefin) with a melting point of 56-70°C provides candle formulators flexibility to use a wider variety of melting point paraffins. The new poly (alpha olefin) can be used as a mold release agent in polyurethane foams imparting a smooth surface to the foam, and provides manufacturers greater flexibility in their operating and demolding temperatures. The poly (alpha olefin) produced by the novel process of the present subject matter possesses a tighter PDI (polydispersity index), which is important for lipstick structuring, and provides improved mold release in a lipstick mold. The material also can aid in the manufacture of personal care products such as lipstick, structuring wax, glossing agents, and body lotions.

SUMMARY OF THE INVENTION

[0005] The subject matter of the present disclosure relates to a method for polymerizing alpha-olefins to produce poly (alpha-olefins) having improved properties.

[0006] In one embodiment the present disclosure provides a process comprising polymerizing a feed stream to form a poly (alpha olefin) stream with a free radical initiator having an initiator loading at a temperature of 40 to 250 °C, and a pressure of 14.7 to 500 psig, wherein the feed stream comprises alpha-olefins of the formula RCH=CH2, where R is C to Ceo, with a C24/C28 ratio of 1 .0 to 1 .7, a ratio of C26/C28 of 1 .0 to 1 .3, and the sum of C24, C26, and C28 material is from 40.0 to 70.0 wt%, and iso/branched olefins, and where the poly (alpha olefin) stream having a softening point of 50 °C-80 °C.

[0007] In another embodiment, the present disclosure provides a poly (alpha-olefin) produced by a process comprising polymerizing a feed stream a free radical initiator having an initiator loading at a temperature of 40 to 250 °C, and a pressure of 14.7 to 500 psig, wherein the feed stream comprises alpha-olefins of the formula RCH=CH2, where R is C to Ceo, with a C24/C28 ratio of 1 .0 to 1 .7, a ratio of C26/C28 of 1 .0 to 1 .3, and the sum of C24, C26, and C28 material is from 40.0 to 70.0 wt%, and iso/branched olefins, and where the poly (alpha olefin) stream having a softening point of 50 °C-80 °C.

[0008] Additional features and advantages of the described embodiments will be set forth in the detailed description which follows, and in part will be readily apparent to those skilled in the art from that description or recognized by practicing the described embodiments, including the detailed description which follows as well as the claims.

DETAILED DESCRIPTION OF THE INVENTION

[0009] The subject matter of the present disclosure provides a process for the polymerization of alpha-olefins to produce a poly (alpha-olefin). [0010] In one embodiment the present disclosure provides a process comprising polymerizing a feed stream to form a poly (alpha olefin) stream with a free radical initiator having an initiator loading at a temperature of 40 to 250 °C, and a pressure of 14.7 to 500 psig, wherein the feed stream comprises alpha-olefins of the formula RCH=CH2, where R is C to Ceo, with a C24/C28 ratio of 1 .0 to 1 .7, a ratio of C26/C28 of 1 .0 to 1 .3, and the sum of C24, C26, and C28 material is from 40.0 to 70.0 wt%, and iso/branched olefins, and where the poly (alpha olefin) stream has a softening point of 50 °C-80 °C.

[0011] Polymerization

[0012] The polymerization of the inventive process is a free radical polymerization conducted in a reaction vessel where the alpha-olefin stream is polymerized to a poly (alpha-olefin) using a reaction initiator. The polymerization process can be batch or continuous. The reaction vessel can be an autoclave or tubular reactor, and can be constructed of any material suitable to the temperatures, pressures and characteristics of the materials being processed. Preferably, the reaction vessel is made of stainless steel. When the reaction vessel is an autoclave, the reaction vessel can be equipped with an agitator for mixing. Heat transfer coils can be provided either internally or externally, e.g., heat exchangers equipped with a pump around system, or overhead condensers.

[0013] The polymerization can be conducted without solvent, i.e., just the alpha-olefin monomer and the initiator. The polymerization can also be conducted with a solvent as a solution polymerization. Preferably the solvent is an aromatic solvent. More preferably, the solvent is selected from toluene, xylene, trimethylbenzene, naphtha, alkyl aromatics or mixtures thereof.

[0014] The temperature of the polymerization reaction is typically 40°C to 250°C. Preferably, the temperature of the polymerization reaction is 55°C to 200°C. More preferably, the temperature of the polymerization reaction is 140°C to 150°C.

[0015] The pressure of the polymerization reaction is typically 14.7 to 500 psig. Preferably, the pressure of the polymerization reaction is 14.7 to 100 psig. More preferably, the pressure of the polymerization reaction is 30.0 to 60.0 psig. Most preferably, the pressure of the polymerization reaction is 40.0 to 50.0 psig. [0016] The polymerization reaction utilizes an initiator, where the initiator thermally decomposes to a radical species, which reacts with an olefin or hydrocarbons to transfer the radical and initiate the polymerization. The radical olefin and radical hydrocarbons react with other olefins and hydrocarbons to grow the polymer chain.

[0017] Preferably, the initiator is selected from the group consisting of organic peroxides, organic hydroperoxides, hydrogen peroxide, inorganic peroxy compounds and azo compounds. More preferably, the initiator is selected from organic peroxides and organic hydroperoxides. Even more preferably the initiator is di-tert-butyl peroxide.

[0018] The typical loading of the initiator is 2 to 20 wt% in the polymerization, where the wt% relates to the total weight of the initiator and alpha-olefin monomer.

[0019] Typically, the duration of the polymerization reaction is 4 to 24 hours.

[0020] Alpha-Olefin Feedstock

[0021] The alpha-olefin feedstock used as the feed stream in the inventive polymerization process has particularly selected properties to provide the properties desired in the polymerized product.

[0022] The feed stream comprises alpha-olefins of the formula RCH=CH2, where R is Cis to Ceo, and iso/branched olefins.

[0023] The feed stream has a C24/C28 ratio of 1 .0 to 1 .7. Preferably, the C24/C28 ratio is 1.1 to 1 .6. More preferably, the C24/C28 ratio is 1 .2 to 1 .5.

[0024] The feed stream has a ratio of C26/C28 of 1 .0 to 1 .3. Preferably, the C26/C28 ratio is 1 .1 to 1 .2.

[0025] Preferably, the sum of C24, C26, and C28 material in the feed stream is from 40.0 to 70.0 wt%. More preferably, the sum of C24, C26, and C28 material in the feed stream is from 50.0 to 60.0 wt%.

[0026] Preferably, the iso/branched olefin is present in the feed stream at a level of less than 15.0 wt%. More preferably, the iso/branched olefin is present in the feed stream at a level of less than 10.0 wt%.

[0027] Preferably, the C24 material is present in the feed stream in an amount from 21 .0 to 25.0 wt.%. More preferably, the C24 material is present in the feed stream in an amount of 22.0 to 24.0 wt.%. [0028] Preferably, the C26 material is present in the feed stream in an amount from 16.0 to 20.0 wt%. More preferably, the C26 material is present in the feed stream in an amount of 17.0 to 19.0 wt%.

[0029] Preferably, the C28 material is present in the feed stream in an amount from 10.0 to 16.0 wt%. More preferably, the C28 material is present in the feed stream in an amount of from 12.0 to 14.0 wt%.

[0030] Preferably, the feed stream has a congealing point measured according to ASTM D-938 of 57 to 60°C.

[0031] Preferably, the feed has a kinematic viscosity, measured according to ASTM D- 445 of 4-5 at 100°C.

[0032] Such feed streams are commercially available from SHOP (Shell Higher Olefins Process).

[0033] Poly (alpha-olefin) Product

[0034] The poly (alpha-olefin) product of the inventive process has a softening point ring & ball, measured according to ASTM D36 MOD, of 50 to 80°C. Preferably, the softening point is 60 to 71 °C. More preferably, the softening point is 62 to 68°C.

[0035] The poly (alpha-olefin) product of the inventive process also has a color, measured according to ASTM D1500 MOD, of less than or equal to 0.5. Preferably, the color is less than or equal to 0.4. More preferably the color is 0.1 to 0.3.

[0036] The poly (alpha-olefin) product of the inventive process has a viscosity Brookfield @ 210°F, measured according to ASTM D3236 MOD, of 245.0 to 440.0 cps. Preferably, the viscosity is 280 to 325 cps.

[0037] The poly (alpha-olefin) product of the inventive process has a needle penetration at 25°C (DMM), measured according to ASTM D1321 MOD, of 4.0 to 8.0. Preferably, the needle penetration is 5.0 to 7.0.

[0038] The poly (alpha-olefin) product of the inventive process has a flash point, COC, measured according to ASTM D92 MOD, of greater than or equal to 232.2°C.

[0039] The poly (alpha-olefin) product of the inventive process has a number average molecular weight, measured according to Gel Permeation Chromatography, of 600 to 7000 g/mol measured according to ASTM D6474-20. Preferably, the number average molecular weight is 1000 to 6000.

[0040] Examples

[0041] The following examples illustrate one or more additional features of the present disclosure described. These examples are not intended to limit the scope of the disclosure or the appended claims in any manner.

[0042] Example 1

[0043] 400 grams of Shell Neodene C26+ olefin was mixed with 40 grams of di-t-butyl peroxide. Neodene C26+ is summarized in Table 1 . The mixture was heated at 145 °C for 6 hours under 1 atmosphere nitrogen. A sample was drained and flashed with nitrogen at 130 °C to remove the decomposition products of peroxides (t-butyl alcohol and acetone) and di-t-butyl peroxide residue. The physical properties of the sample were measured using ASTM procedures, and are summarized in Table 2.

Table 1

Table 2 [0044] Example 2

[0045] 100 parts of Shell Neodene C26+ olefin was mixed with 8 parts of di-t-butyl peroxide (weight ratio equals to 100: 8). The mixture was heated at 145°C for 22 hours under nitrogen in an autoclave. A sample was drained and then vacuum stripped until bubbling stopped to remove the decomposition products of peroxides (t-butyl alcohol and acetone). The physical property of the sample was measured using ASTM procedures, and are summarized in Table 3.

Table 3

[0046] Having described the subject matter of the present disclosure in detail and by reference to specific embodiments, it is noted that the various details described in this disclosure should not be taken to imply that these details relate to elements that are essential components of the various embodiments described in this disclosure. Rather, the claims below should be taken as the sole representation of the breadth of the present disclosure and the corresponding scope of the various embodiments described in this disclosure. Further, it should be apparent to those skilled in the art that various modifications and variations can be made to the described embodiments without departing from the spirit and scope of the claimed subject matter. Thus, it is intended that the specification cover the modifications and variations of the various described embodiments provided such modification and variations come within the scope of the appended claims and their equivalents.